The monster films win the race. Monsters Vs. Aliens premiered this weekend in the Number One spot at the box office with $58.2 Million. The Haunting in Connecticut premiered this weekend in Second Place with $23 Million. Knowing was Third with $14.7 Million. I Love You, Man was Fourth with $12.6 Million. Duplicity was Fifth with $7.5 Million. Race to Witch Mountain, 12 Rounds (which premiered this weekend), Watchmen, Taken and The Last on the Left (2009) rounded out the top ten respectively.
Source: Box Office Mojo